class_docstr: Randomly decides who speaks next.
code: def act(self):
      assert hasattr(self, "characters"), "Personas are not set."
      return {
          "text": random.choice(self.characters),
          "id": "RandomOrderDecision",
          "episode_done": False,
      }
  
imports: from typing import Optional, Dict
  import random
  from parlai.core.agents import Agent
  from parlai.core.opt import Opt
  from parlai.core.params import ParlaiParser
  from parlai.core.agents import create_agent_from_model_file
  from parlai.core.loader import load_agent_module
  from parlai.utils.logging import logging
label_desc: Use image node_id 2 for calling the RandomSpeakerDecicionsAgent obj's underlying member method code with example usage: obj.act() and returns: dict